Tropical Storm Flossie continued its westward march toward Hawaii where it was expected to weaken before it brings heavy rain to the Big Island of Hawaii early Monday then tracking south to Oahu several hours later.
The sixth named storm of the eastern Pacific hurricane season triggered tropical storm warnings -- where the storm was expected to hit within 36 hours -- for Hawaii county, Oahu, and Maui county, which includes the islands of Maui, Molokai, Lanai and Kahoolawe, the National Weather Service said Sunday evening.
A tropical storm watch was in effect for Kauai and Niihau islands.
Flossie was packing maximum sustained winds of about 57 mph with stronger gusts, according to the National Service.
However, drier air, increased wind shear and cooler water temperatures were expected to weaken Flossie as it moves over the islands, The Weather Channel reported, though it is forecast to remain a tropical storm through Wednesday.
A flash flood watch was issued throughout the islands from Monday through Tuesday night, the Honolulu Star Advertiser reported.
Upwards of 15 inches of rain were expected in windward areas of Maui and Hawaii counties, and 6 to 10 inches elsewhere, forecasters said. Up to a foot of rain may be seen in part of Oahu.
"Rock and mudslides caused by the rainfall will be possible around or near mountain slopes. The heavy rain will also fall over urban areas in the lower elevations, which will be more susceptible to flooding problems," the National Weather Service said.
The Associated Press contributed to this report.